U.S. patent number 5,057,361 [Application Number 07/439,062] was granted by the patent office on 1991-10-15 for wettable polymeric fabrics.
This patent grant is currently assigned to Kimberly-Clark Corporation. Invention is credited to Cheryl A. Perkins, John J. Sayovitz.
United States Patent |
5,057,361 |
Sayovitz , et al. |
October 15, 1991 |
Wettable polymeric fabrics
Abstract
A polymeric fabric having enhanced wettability, a method for
producing such wettable polymeric fabric, and composition for us in
the method are provided. The polymeric fabric comprises a primary
surfactant on the surface of the polymeric fabric, the primary
surfactant having a low solubility in water and dispersible in
water. The primary surfactant is applied to the fabric in an
aqueous solution. The primary surfactant is preferably applied to
the fabric in a composiiton comprising the primary surfactant,
water, and a co-surfactant functional to wet the polymeric fabric
with the composition during application of the composition to the
polymeric fabric. The co-surfactant is present in the composition
in an amount sufficient to provide for substantially uniform
distribution of the primary surfactant onto the polymeric
fabric.
Inventors: |
Sayovitz; John J. (Marietta,
GA), Perkins; Cheryl A. (Marietta, GA) |
Assignee: |
Kimberly-Clark Corporation
(Neenah, WI)
|
Family
ID: |
23743129 |
Appl.
No.: |
07/439,062 |
Filed: |
November 17, 1989 |
Current U.S.
Class: |
442/118;
106/287.13; 106/287.16; 106/287.23; 428/447; 524/800; 524/837;
442/170 |
Current CPC
Class: |
D06M
15/643 (20130101); D06M 13/144 (20130101); Y10T
442/291 (20150401); Y10T 442/2484 (20150401); Y10T
428/31663 (20150401) |
Current International
Class: |
D06M
13/144 (20060101); D06M 15/643 (20060101); D06M
15/37 (20060101); D06M 13/00 (20060101); B32B
027/00 () |
Field of
Search: |
;418/266,290,447
;524/800,837 ;106/287.13,287.16,287.23 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
|
|
|
|
|
|
|
1198096 |
|
Jul 1970 |
|
GB |
|
1220471 |
|
Jan 1971 |
|
GB |
|
1220472 |
|
Jan 1971 |
|
GB |
|
Other References
Primary Examiner: Bell; James J.
Attorney, Agent or Firm: Herrick; William D.
Claims
We claim:
1. A composition for increasing the wettability of polymeric
fabric, the composition comprising:
a primary surfactant of the type having a low solubility in water
and dispersible in water;
water; and
a co-surfactant functional to wet the polymeric fabric with the
composition during application of the composition to the polymeric
fabric, and present in an amount sufficient to provide for
substantially uniform distribution of the primary surfactant onto
the polymeric fabric.
2. A composition as in claim 1, wherein the primary surfactant has
a cloud point less than about 50.degree. C.
3. A composition as in claim 1, wherein the primary surfactant is
selected from the group consisting of organosilicones, polyethylene
oxides, a polyalkylene oxide modified castor oil.
4. A composition as in claim 2, wherein the primary surfactant
comprises an organosilicone.
5. A composition as in claim 4, wherein the co-surfactant is
selected from the group consisting of primary alcohols and
secondary alcohols.
6. A composition as in claim 5, wherein:
the primary surfactant is present in an amount of from about 0.1
percent to about 3.0 percent by weight of the composition; and
the co-surfactant is present in an amount of from about 0.05
percent to about 0.6 percent by weight of the composition.
7. A composition as in claim 2, wherein the primary surfactant is
selected from the group consisting of polyalkylene oxide modified
siloxanes and silanes.
8. A composition as in claim 7, wherein the co-surfactant is
selected from a group consisting of primary alcohols and secondary
alcohols.
9. A composition as in claim 8, wherein:
the primary surfactant is present in an amount of from about 0.1
percent to about 3.0 percent by weight of the composition; and
the co-surfactant is present in an amount of from about 0.05
percent to about 0.6 percent by weight of the composition.
10. A wettable polymeric fabric comprising:
a normally water repelling polymeric fabric having a surface; and a
primary surfactant having a cloud point less than about
50.degree.C. substantially uniformly distributed on the surface of
the polymeric fabric, the primary surfactant also having a low
solubility in water and being dispersible in water.
11. A wettable polymeric fabric as in claim 10, wherein the primary
surfactant is selected from the group consisting of
organosilicones, polyethylene oxides, and polyalkylene oxide
modified castor oil.
12. A wettable polmeric fabric as in claim 10, where in the primary
surfactant comprises an organosilicone.
13. A wettable polymeric fabric as in claim 12, wherein the primary
surfactant is present in an amount of about 0.1 percent to about
0.3 percent by weight of the wettable polymeric fabric.
14. A wettable polymeric fabric as in claim 10, wherein the primary
surfactant is selected from the group consisting of polyalkylene
oxide modified siloxanes and silanes.
15. A wettable polymeric fabric as in claim 14, wherein the primary
surfactant is present in an amount of about 0.1 percent to about
0.3 percent by weight of the wettable polymeric fabric.
16. A wettable non-woven polymeric fabric comprising:
a normally water repelling non-woven polyolefin fabric having a
surface; and
a primary surfactant having a cloud point less than about
50.degree. C. substantially uniformly distributed on the surface of
the polymeric fabric, the surfactant having a low solubility in
water and being dispersible in water.
17. A wettable polymeric fabric as in claim 16, wherein the primary
surfactant is selected from the group consisting of
organosilicones, polyethylene oxides, and polyalkylene oxide
modified castor oil.
18. A wettable polymeric fabric as in claim 16, wherein the primary
surfactant comprises an organosilicone.
19. A wettable polymeric fabric as in claim 18, wherein the primary
surfactant is present in an amount of about 0.1 percent to about
0.3 percent by weight of the wettable polymeric fabric.
20. A wettable polymeric fabric as in claim 16, wherein the primary
surfactant is selected from the group consisting of polyalkylene
oxide modified siloxanes and silanes.
21. A wettable polymeric fabric as in claim 20, wherein the primary
surfactant is present in an amount of about 0.1 percent to about
0.3 percent by weight of the wettable polymeric fabric.
22. A process for increasing the wettability of polymeric fabric,
the process comprising the steps of:
providing a polymeric fabric having a surface; and
applying to the surface of the polymeric fabric a composition
comprising water and a primary surfactant of the type having a low
solubility in water and dispersible in water, said application
resulting in substantially uniform distribution of said primary
surfactant.
23. A process as in claim 22, wherein the primary surfactant has a
cloud point less than about 50.degree. C.
24. A process as in claim 23, wherein the primary surfactant is
selected from the group consisting of organosilicones, polyethylene
oxides, and polyalkylene oxide modified castor oil.
25. A process as in claim 23, wherein the primary surfactant
comprises an organosilicone.
26. A process as in claim 25, wherein the step of applying the
primary surfactant is carried out so as to add the primary
surfactant to the polymeric fabric in an amount from about 0.1
percent to about 0.3 percent by weight of the wettable polymeric
fabric.
27. A process as in claim 25, wherein:
the primary surfactant is present in the composition in an amount
of about 0.1 percent to about 3.0 percent by weight of the
composition.
28. A process as in claim 23, wherein the primary surfactant is
selected from the group consisting of polyalkylene oxide modified
siloxanes and silanes.
29. A process as in claim 28 wherein the step of applying the
primary surfactant is carried out so to add the primary surfactant
to the polymeric fabric in an amount from about 0.1 percent to
about 0.3 percent by weight of the wettable polymeric fabric.
30. A process as in claim 28, wherein
the primary surfactant is present in the composition in an amount
of about 0.1 percent to about 3.0 percent by weight of the
composition.
31. A process as in claim 22, wherein the composition applied to
the surface of the polymeric fabric further comprises a
co-surfactant functional to wet the surface of the polymeric fabric
with the composition during the application step, and present in
the composition in an amount sufficient to provide for
substantially uniform distribution of the primary surfactant onto
the surface of the polymeric fabric.
32. A process as in claim 31, wherein the primary surfactant has a
cloud point less that about 50.degree. C.
33. A process as in claim 32, wherein the primary surfactant is
selected from the group consisting of organosiicones, polyethylene
oxides, and polyalkylene oxide modified castor oil.
34. A process as in claim 32, wherein the primary surfactant
comprises an organosilicone.
35. A process as in claim 34, wherein the co-surfactant is selected
from the group consisting of primary alcohols and secondary
alcohols.
36. A process as in claim 35, wherein:
the primary surfactant is present in an amount of from about 0.1
percent to about 3.0 percent by weight of the composition; and
the co-surfactant is present in an amount of from about 0.05
percent to about 0.6 percent by weight of the composition.
37. A process as in claim 35, wherein the step of applying the
primary surfactant is carried out so as to add the primary
surfactant to the polymeric fabric in an amount from about 0.1
percent to about 0.3 percent by weight of the wettable polymeric
fabric.
38. A process as in claim 32, wherein the primary surfactant is
selected from the group consisting of polyalkylene oxide modified
siloxanes and silanes.
39. A process as in claim 38, wherein the co-surfactant is selected
from the group consisting of primary alcohols and secondary
alcohols.
40. A process as in claim 39, wherein:
the primary surfactant is present in an amount of from about 0.1
percent to about 3.0 percent by weight of the composition; and
the co-surfactant is present in an amount of from about 0.05
percent to about 0.6 percent by weight of the composition.
41. A process as in claim 39, wherein:
the step of applying the primary surfactant is carried out so as to
add the primary surfactant to the polymeric fabric in an amount
from about 0.1 percent to about 0.3 percent by weight of the
wettable polymeric fabric.
Description
TECHNICAL FIELD
This invention generally relates to polymeric fabrics, and more
particularly relates to surface treatments for improving the
wettability of polymeric fabrics.
BACKGROUND OF THE INVENTION
Polymeric fabrics are used to make a variety of products, some of
which require the polymeric fabrics to absorb water. Such products
include towels, industrial wipes, infant care products such as baby
diapers, and feminine care products such as tampons. Polyolefin
non-woven fabrics are polymeric fabrics which are particularly
suited for these type products. This is because polyolefin
non-woven fabrics are relatively economically produced.
Polyolefin non-woven fabrics and other types of polymeric fabrics
tend to repel water. Thus, to effectively absorb water, the surface
of polyolefin non-wovens and other types of polymeric fabrics are
often surface treated with compositions which increase the
wettability, of the fabric. One such conventional surface treatment
is octylphenoxypolyethoxy ethanol, a non-ionic surfactant.
There are some problems with conventional surface treatment
compositions used to increase the wettability of polymeric fabrics.
For example, conventional surface treatment compositions are
relatively easily rubbed off the fabric and are also easily washed
off the fabric when the fabric is wetted. Conventional surface
treatment compositions are often substantially completely removed
from the polymeric fabric after only one washing. After the surface
treatment is removed, the polymeric fabric again becomes water
repellent and less effective to absorb water. Moreover, to
compensate for the inability of conventional surface treatments to
survive use, conventional surface treatments are often applied to
polymeric fabrics in large quantities which increases the cost of
the treated fabric. In addition to the foregoing, conventional
surface treatment compositions are often skin irritants and thus
are undesirable as surface treatments for fabrics used to make
infant care products and feminine care products.
Therefore, there is a need for a surface treatment for improving
the wettability of polymeric fabrics which survives repeated use
and washing of the fabric, is less of a skin irritant and
essentially medically safe, and is economical.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a polymeric fabric
having enhanced wettability.
Another object of the present invention is to provide an improved
surface treatment for enhancing the wettability of polymeric
fabric.
Another object of the present invention is to provide a surface
treatment which enhances the wettability of polymeric fabric and
survives repeated use and washing of the polymeric fabric.
Still another object of the present invention is to provide a more
economical surface treatment which enhances the wettability of
polymeric fabric.
A further object of the present invention is to provide a surface
treatment which enhances the wettability of polymeric fabric and is
medically safe.
Accordingly, there is provided a polymeric fabric having enhanced
wettability comprising a primary surfactant on the surface of the
polymeric fabric, the primary surfactant having a low solubility in
water and dispersible in water. The present invention also
comprehends processes for applying the primary surfactant in an
aqueous solution to the surface of the polymeric fabric. In
addition, the present invention provides a composition which when
applied to polymeric fabric increases the wettability of the
polymeric fabric.
The composition of the present invention comprises the primary
surfactant, water, and a co-surfactant functional to wet the
polymeric fabric with the composition during application of the
composition to the polymeric fabric. The co-surfactant is present
in the composition in an amount sufficient to provide for
substantially uniform distribution of the primary surfactant onto
the polymeric fabric.
Stated more particularly, the primary surfactant has a cloud point
less than about 50.degree. C. Such primary surfactants include
organosilicones, polyethylene oxides, and polyalkylene-oxide
modified castor oil. More specifically, the primary surfactants
include polyalkylene oxide modified siloxanes and silanes. In a
preferred embodiment, the primary surfactant comprises polyalkylene
-oxide modified polydimethyl-siloxane.
Stated still more particularly, co-surfactants include, but are not
limited to, primary alcohols and secondary alcohols.
In a preferred embodiment, the composition of the present invention
includes the primary surfactant in an amount of about 0.1% to about
3.0% by weight of the composition and the co-surfactant in an
amount of about 0.05% to about 0.6% of the composition. In a
preferred embodiment of the fabric of the present invention, the
primary surfactant is present on the surface of the polymeric
fabric in an amount of about 0.1% to about 0.3% by weight of the
treated polymeric fabric.
Polymeric fabrics surface treated with primary surfactant in
accordance with the present invention exhibit enhanced wettability
and are advantageously used to make water absorbent products. The
surface treated polymeric fabrics of the present invention remain
wettable after repeated wettings and thus may be reused.
Accordingly, surface treated polymeric fabric of the present
invention are more economical than conventional surface treated
polymeric fabrics. The surface treated fabrics of the present
invention tend to be medically safe. This is a particular advantage
when the surface treated fabrics of the present invention are used
to make infant wear and feminine care products.
Other features, objects, and advantages of the present invention
will become apparent from the following detailed description,
drawings, and claims.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a partial perspective view of a spray applications system
wherein the surface treatment of the present invention is applied
to polymeric fabric.
FIG. 2 is a partial perspective view of a liquid applications
system wherein the surface treatment of the present invention is
applied to polymeric fabric.
DETAILED DESCRIPTION OF THE INVENTION
The present invention provides for a polymeric fabric having
enhanced wettability, a method for producing such wettable
polymeric fabric, and a composition for use in the method. The
polymeric fabrics of the present invention are suitable to make
products which are used to absorb water such as towels, industrial
wipes, infant care products such as diapers, and feminine care
products such as tampons.
Types of polymeric fabrics which are particularly useful when
surface treated according to the present invention include
polyolefin non-woven fabrics, because such fabrics exhibit good
absorbency characteristics and are relatively economically
produced. Common polyolefin non-woven fabrics include polypropylene
and polyethylene spunbonded fabrics. Such fabrics and typically
produced by processes disclosed in the following patents:
______________________________________ Appel, et al. 4,340,563
Dorschner, et al. 3,692,618 Kinney 3,338,992 Kinney 3,341,394 Levy
3,502,538 Hartmann 3,502,763 Hartmann 3,909,009 Dobo, et al.
3,542,615 Harmon (Canadian) 803,714
______________________________________ These polyolefin non-wovens
show substantially improved wettability when treated in accordance
with the present invention as described below.
The wettability of polymeric fabric is enhanced according to the
present invention by applying a primary surfactant onto the surface
of the polymeric fabric. Generally described, the primary
surfactants are of type having a low solubility in water and
dispersible in water. More particularly, the primary surfactants
are of the type having a cloud point less than or equal to about
50.degree. C. The cloud point of a surfactant is the temperature at
which aqueous solutions of the surfactant become cloudy when cooled
at a specified rate. The cloud point data provided herein was
measured using a one percent solution of the surfactant in
water.
Suitable primary surfactants include organosilicones, polyethylene
oxides, and polyalkylene-oxide modified castor oil. Preferred
organosilicones include polyalkylene oxide modified siloxanes and
silanes. Polyalkylene-oxide modified castor oil is a castor oil
having one or more polyalkylene-oxide groups attached to the main
carbon chain of the caster oil. Likewise, polyalkylene-oxide
modified siloxanes are siloxanes having polyalkylene oxide groups
attached to the main carbon chain of the siloxanes. These
polyalkylene oxide modifications are well known to those of
ordinary skill in the art. A particularly preferred primary
surfactant is Y-12230 polyalkylene-oxide modified polydimethyl
siloxane produced by Union Carbide.
The wettable polymeric fabric of the present invention preferably
comprises primary surfactant in an amount of about 0.1 to about 3.0
percent by weight of the wettable polymeric fabric. According to a
more preferred embodiment of the present invention, the wettable
polymeric fabric comprises primary surfactant in an amount of about
0.15 to about 1.0 percent by weight of the wettable polymeric
fabric.
The primary surfactant is applied to the polymeric fabric as
composition comprising the primary surfactant and water. This
composition preferably comprises primary surfactant in an amount of
about 0.1 percent to about 0.3 percent by weight of the
composition.
According to a more preferred embodiment of the present invention,
the primary surfactant is applied to the polymeric fabric as a
composition comprising the primary surfactant, water, and a
co-surfactant. Generally described, the co-surfactant is a
surfactant functional to wet the polymeric fabric with the
composition during application of the composition to the polymeric
fabric. The co-surfactant is preferably present in the composition
in an amount sufficient to provide for substantially uniform
distribution of the primary surfactant onto the polymeric fabric.
When the primary surfactant is applied to polymeric fabric without
the co-surfactant, the primary surfactant is not uniformly
distributed over the surface of the polymeric fabric; instead, the
primary surfactant tends to accumulate in concentrated zones on the
surface of the fabric while other portions of the fabric surface
remain substantially free of surfactant.
Particularly suitable co-surfactants include primary and secondary
alcohols. Most primary and secondary alcohols and water azeotrope
and evaporate relatively easily during the drying process, so that
the primary and secondary alcohols are substantially completely
evaporated from the treated polymeric fabric during the drying
step. The surface treatment composition of the present invention
preferably comprises co-surfactant in an amount of about 0.05 to
about 0.6 percent by weight of the composition.
It is believed that the primary surfactants are particularly
effective as surface treatments for polymeric fabrics for the
following reasons. First, the primary surfactants are dispersible
in water, and thus can be applied to polymeric fabrics in an
aqueous dispersion. Second, the primary surfactants have a low
solubility in water and thus are not easily washed off the surface
of polymeric fabric after the polymeric fabric has been surface
treated and dried according to the present invention.
Surface treatment methods within the scope of the present invention
include spraying a composition including the primary surfactant
onto polymeric fabric as shown in FIG. 1 and applying a composition
containing the primary surfactant by the liquid application systems
method as shown in FIG. 2. However, it should be understood that
the practice of the present invention is not limited to either of
these particular methods.
Turning first to FIG. 1, a spray application system 10 is shown for
applying a composition containing the primary surfactant to
polymeric fabric 12. The spray application system 10 includes a
pair of guide rollers 15 and 16 through which the polymeric fabric
12 initially passes. The polymeric fabric passes from the guide
rollers 15 and 16 under a spray boom 20 extending across the width
of the polymeric fabric. The spray boom includes a plurality of
spray nozzles 22 spaced along the spray boom 20 and directed
downwardly toward the polymeric fabric 12. The composition
containing the primary surfactant is sprayed through the spray
nozzles 22 onto the polymeric fabric 12 as the polymeric fabric
passes beneath the spray boom 20. The polymeric fabric 12 passes
from beneath the spray boom to a series of drying cans 25. The
drying cans are steam heated to a temperature sufficient to dry the
treated polymeric fabric without damaging the structure of the
polymeric fabric.
A liquid application system 30 for applying a composition
containing the primary surfactant to polymeric fabric 32 is shown
in FIG. 2. The liquid applications system 30 includes a trough 35
containing a composition including the primary surfactant. A
metering roller 38 runs substantially the length of the trough 35
and is partially submerged in the liquid composition contained in
the trough. A transfer roller 40 is positioned above and parallel
to the metering roller 38 so that the outer surface of the transfer
roller is in contact with the outer surface of metering roller. A
backing roller 42 is positioned parallel to, above and slightly to
the side of the transfer roller 40 so that the outer surface of the
backing roller is in contact with the outer surface of the transfer
roller.
During operation of the liquid application system 30, the polymeric
fabric 32 is drawn from a roll 45 through a narrow space between
the transfer roller 40 and the backing roller 42 by the rotation of
the backing roller. The backing roller 42 is rotated clockwise as
shown in FIG. 2 and the transfer roller 40 is preferably rotated
clockwise so that the surface of the transfer roller travels in a
direction opposite the direction of the fabric 32. The metering
roller 38 is driven counterclockwise through the liquid composition
in the trough 35 by the transfer roller 40. As the metering roller
38 rotates, the outer surface of the metering roller carries the
surface treatment composition from the trough 35 to the outer
surface of the transfer roller 40. The transfer roller 40 then
carries the surface treatment composition to the narrow space
between the transfer roller and the backing roller 42 and in
contact with the surface of the polymeric fabric 32 passing between
the transfer roller and the backing roller. The polymeric fabric 32
passing between the transfer roller 40 and the backing roller 42 is
thus treated, by reverse roll coating, with the surface treatment
from the trough 35. The treated polymeric fabric 32 is then dried
leaving the primary surfactant on the surface of the polymeric
fabric.
This invention is further illustrated by the following examples
which are illustrative of certain embodiments designed to teach
those of ordinary skill in the art how to practice this invention
and to represent the best mode contemplated for carrying out this
invention.
EXAMPLE 1
Polypropylene spunbonded diaper liner fabric having a basis weight
of 0.75 ounces per square yard was surface treated with a surface
treatment composition using the spray application system 10 shown
in FIG. 1. The surface treatment composition comprised 0.40 weight
percent Y-12230 polyalkylene-oxide modified polydimethyl-siloxane,
which has a cloud point less than 10.degree. C. and is produced by
Union Carbide, 0.30 weight percent hexanol, and water as the
remainder. The fabric line speed was 90 feet per minute and the
flow rate of the surface treatment composition from the spray boom
onto the fabric was 0.115 gallons per minute. The wet pick up of
the fabric was 75 weight percent. The steam heated drying cans were
operated at 25 psig (245.degree. F.). The dry weight add-on of the
modified polydimethyl siloxane was 0.29 weight percent of the
treated fabric.
The dried treated fabric from Example 1 was subjected to a run-off
test, the procedure of which was as follows. A 5 inch.times.15 inch
piece of the treated fabric was placed flat on top of an absorbent
medium which was positioned at a 30.degree. inclined plane. A
funnel was placed above the fabric. 100 mls of distilled water at
35.degree. C..+-.0.6.degree. C. was dispensed from the funnel onto
the fabric over a time period of 15 seconds.+-.1.5 seconds. Any of
the distilled water that was not absorbed by the fabric ran off the
fabric and was collected. The volume of run-off water was
measured.
After the run-off test the piece of treated fabric was removed from
the inclined plane and washed in a container of water. The piece of
treated fabric was submerged in 500 mls of water at 25.degree. C.
The treated fabric was agitated in the water for one minute.
The piece of treated fabric was then removed from the container of
water and dried in an oven at 200.degree. F. for eight minutes. The
piece of treated fabric was repeatedly subjected to the run-off
test and then washed according to the foregoing procedure until the
amount of run-off water from the run-off test exceeded 20 mls. The
results of each run-off test of Example 1 are shown in Table 1.
EXAMPLE 2
A comparative example of treated fabric was prepared by treating
polypropylene spunbonded fabric with a conventional surface
treatment composition according to the process described in Example
1. The conventional surface treatment composition comprised 0.33
weight percent Triton X-102, and actyl-phenoxypolyethoxy ethanol
non-ionic surfactant which has a cloud point of 88.degree. C. and
is produced by Rohm and Haas. The dry add-on of the Triton X-102
surfactant was 0.21 percent by weight of the treated fabric.
The treated fabric from Example 2 was subjected to the same run-off
tests and washings as the treated fabric from Example 1 and the
results of such tests are shown in Table 1. As can be seen from
Table 1, the fabric from Example 1 treated in accordance with the
present invention remained absorbent even after repeated washings,
whereas the fabric from Example 2 treated with convention surface
treatments did not.
TABLE 1 ______________________________________ Example 1 Example 2
Run-Off Test Run-Off Water (mls) Run-Off Water (mls)
______________________________________ Initial 0.0 0.0 After 1st
wash 0.0 93.7 After 2nd wash 0.0 -- After 3rd wash 60.3 --
______________________________________
EXAMPLE 3
Polypropylene spunbonded diaper liner fabric having a basis weight
of 0.75 ounces per square yard was surface treated with a surface
treatment composition using the liquid application system 30 shown
in FIG. 2. The surface treatment composition comprised 1.67 weight
percent Y-12230 polyalkylene oxide modified polydimethyl-siloxane
produced by Union Carbide, 0.30 weight percent hexanol, and water
as the remainder. The fabric line speed was 500 feet per minute,
the metering roller speed was 200 feet per minute, and the transfer
roller speed was 1100 feet per minute. The wet treated fabric was
dried by passing the fabric over the surface of steam heated dryer
cans operating at 250.degree. F. The dry weight add-on of the
modified polydimethyl siloxane was 0.52 percent by weight of the
treated fabric.
The treated fabric from Example 3 was subjected to the same run-off
tests and washings as the treated fabric from Example 1 and the
results of such tests are shown in Table 2. As shown in Table 2,
the fabric from Example 3 treated in accordance with the present
invention remained absorbent after repeated washings.
EXAMPLE 4
Polypropylene spunbonded diaper liner fabric having a basis weight
of 0.75 ounces per square yard was surface treated according to the
same procedure described in Example 3 except that the surface
treatment composition comprised 2.50 weight percent Y-12230
polyalkylene oxide modified polydimethyl siloxane produced by Union
Carbide and 0.6 weight percent hexanol and the transfer roller
speed was 1300 feet per minute. The dry weight add-on of the
modified polydimethyl siloxane was 0.81 percent by weight of the
treated fabric.
The treated fabric from Example 4 was subjected to the same run-off
tests and washings as the treated fabric from Example 1 and the
results of such tests are shown in Table 2. The fabric from Example
4 treated in accordance with the present invention also remained
absorbent after repeated washings.
TABLE 2 ______________________________________ Example 3 Example 4
Run-Off Test Run-Off Water (mls) Run-Off Water (mls)
______________________________________ Initial 0.0 0.0 After 1st
wash 0.0 0.0 After 2nd wash 0.3 0.2 After 3rd wash 67.6 34.7
______________________________________
EXAMPLE 5
Polypropylene spunbonded diaper liner fabric having a basis weight
of 0.75 ounces per square yard was surface treated according to the
same procedure described in Example 1 except that the surface
treatment composition comprised 0.40 weight percent TEGOPREN 5863
polyalkylene oxide modified polydimethyl siloxane which has a cloud
point of 44.degree..+-.3.degree. C. and is produced by Goldschmidt
Chemical of West Germany, and 0.05 weight percent GEMTEX SM-33
surfactant produced by Finetex Corporation. The dry weight add-on
of the modified polydimethyl siloxane was 0.37 percent by weight of
the treated fabric.
The treated fabric from Example 5 was subjected to the same run-off
tests and washings as the treated fabric from Example 1 and the
results of such tests are shown in Table 3. As shown in Table 3,
the fabric from Example 5 treated in accordance with the present
invention remained absorbent even after repeated washings.
TABLE 3 ______________________________________ Example 5 Run-Off
Test Run-Off Water (mls) ______________________________________
Initial 0.0 After 1st wash 0.0 After 2nd wash 0.0 After 3rd wash
90.0 ______________________________________
It should be understood that the foregoing relates only to
preferred embodiments of the present invention, and that numerous
changes therein may be made without departing from the spirit and
scope of the invention as defined by the following claims.
* * * * *